Frequency dispersion of the dielectric coefficients and conductivity of Tl$_6$SI$_4$ crystals

The experimental results on the frequency dependences of the dielectric characteristics and conductivity of the grown Tl$_6$SI$_4$ crystals have allowed revealing the nature of the dielectric losses and the hopping mechanism of charge transfer, estimating the parameters of localized states in the band gap, including the density of states near the Fermi level and their energy scatter, the average hopping time, the average hopping length, and the density of deep traps responsible for the alternating-current (ac) conductivity.